IAA对高盐废水培养微藻生长特性与氮磷去除的影响

Effect of IAA on Growth Characteristic and Nitrogen/Phosphorus Removal of Cultivation Microalgae with High-salt Wastewater

废水中高浓度的盐会抑制微藻的生长,通过添加外源植物激素吲哚乙酸(IAA)来促进微藻在盐胁迫下的生长,同时考察不同微藻和盐离子种类对高盐废水培养微藻生长特性与氮磷去除的影响。结果表明,流加模式下培养28 d,小球藻、链带藻、四尾栅藻的最高生物量分别为0.55、0.66、0.75 g/L,总氮和氨氮去除率分别为70.7%、88.5%、79.7%和90.7%、92.6%、92.4%,总磷去除率均达到90%以上。四尾栅藻在模拟高盐废水培养24 d后,高质量浓度IAA(20 mg/L)对其生长效果最好,生物量最高可达0.403 g/L,低质量浓度IAA(≤2 mg/L)对其无明显促进作用甚至抑制生长;高质量浓度IAA(20 mg/L)的总氮和氨氮的去除效果最好,去除率分别为20%和44.1%;总磷去除率为97.2%,其余5组总磷去除率均维持在15%左右。此外,不同种盐条件下四尾栅藻生物量分别为0.667 g/L(空白组)、0.750 g/L(Cl^(-)组)、0.898 g/L(NH_(4)^(+)组)和1.037 g/L(NH_(4)^(+)+Cl^(-)组),各组氮磷去除效果无明显差别,总氮和氨氮去除率分别在30%和50%左右,总磷去除率90%以上。以上研究表明高浓度IAA在盐胁迫条件下对四尾栅藻生长有明显的促进作用,且NH_(4)^(+)和Cl^(-)混合盐离子组获得的四尾栅藻生物量最高。

The high concentration of salt inhibits the growth of microalgae in wastewater.Indole-3-acetic acid(IAA)was added to promote the growth of microalgae under salt stress.At the same time,the effects of different algae species and salt ion on the growth,nitrogen and phosphorus removal of microalgae cultured in high-salt wastewater were investigated.The results showed that the maximum biomass of Chlorella vulgaris,Desmodesmus sp.and Scenedesmus quadricauda could reach 0.55 g/L,0.66 g/L and 0.75 g/L under the flow-feeding mode.The maximum specific growth rates of Desmodesmus sp.and Scenedesmus quadricauda were 0.18 d^(-1) and 0.17 d^(-1) on the 4th day,while Chlorella vulgaris were 0.14 d^(-1) on the 8th day.The removal rates of TN and NH_(4)^(+)-N were 70.7%,88.5%,79.7%and 90.7%,92.6%,92.4%,respectively.The removal rates of TP were more than 90%.The growth of Scenedesmus quadricauda in the high-concentration IAA(20 mg/L)was the best,and the biomass was up to 0.403 g/L.The growth of Scenedesmus quadricauda in the low-concentration IAA(≤2 mg/L)was not significantly promoted or even inhibited.The removal rates of TN and NH_(4)^(+)-N were 20%and 44.1%in 20 mg/L IAA,respectively.The TP removal rate was 97.2%in 20 mg/L IAA,and the other five groups were maintained at about 15%.In addition,the biomass under different salt conditions was 0.667 g/L(blank group),0.750 g/L(Cl^(-)group),0.898 g/L(NH_(4)^(+) group)and 1.037 g/L(NH_(4)^(+)+Cl^(-)group),respectively.There was no significant difference in the removal efficiency of N and P among all groups.The removal rates of TN and NH_(4)^(+)-N was about 30%and 50%,and TP was more than 90%.The above studies indicated that high concentration of IAA could significantly promote the growth of Scenedesmus quadricauda under salt stress,and the biomass was the highest in mixed group(NH_(4)^(+)+Cl^(-)).Therefore,the research result can provide data support for the subsequent application of microalgae in the treatment of high-salt wastewater.